Electric connectors for outlet boxes



Feb. 28, 1961 L. w. ROSE 2,973,212

ELECTRIC CONNECTORS FOR OUTLET BOXES Filed March 28, 1960 INVENTOR LESLIE W ROSE ATTORNEY United States Patent() 2,913,212 ELECTRIC CONNECTORS FOR OUTLET Boxes Leslie W. Rose, 77 Dunfield Ave, Toronto 7, Ontario, Canada Filed Mar. 28, 1960, set. No. 11,925" 9 Claims. (Cl. 2ss-1s9 The invention relates to improvements in electric connectors of the kind commonly employed for anchoring an electric cable to an ordinary outlet box such as is required, for example, in making a convenience outlet in a wall of a building.

As is well known in the art a standard outlet box is supplied with knock-out discs each of which when re-" moved provides an opening for the introduction of an end of a cable for making an electrical connection. The connector is used to secure the cable to the outlet box and should be capable of application to the various kinds of cables commonly employed in the wiring of buildings.

It is an object of thepresent invention to provide a highly efiicient and serviceable connector of the kind described which is adapted'foruse with all types of sheathed electric conductor cables'ordinarily used in wiring buildings. Such cables may be'of the'metallic kind" and either flexible or non-flexible in character. Phononmetallic sheaf cables embrace the well known flexible electric cables such as those marketed by the proprietors under the trade names B-X and Loomex, for ex ample. More particularly the aim of my invention is to provide a connector having latching elements on its body portion en-gageable with the edge portion of the opening in an outlet box through which a cable is to extend and cooperating with alever clamp which upon being tightened by a screw on the connector body not only secures the connector to the outlet boxbut also functions to clamp thecable firmly in place;

According to my invention theleverclampincludesa return-bent cable-engaging section with a'bightp ortion weakened by a cut-away section through which aclamping screw extends and enables the screw'to act directly on the cable-engaging section whereby to cause it' to be" bent into engagement with the portion of the cable within the connector. According to the arrangement the lever clamp is pivotally mounted-on the-connector and has latching engagement with: the outlet box *as it is caused to clamp the connector. The salient feature of the structure is that the cable-engaging section of the lever clamp bends into clamping engagement with the cable regardless of the size of the'latter. The connector is economical to manufactureand may be usedwith facility. I

The selected embodiments of the invention are-illustrated in theaccompanying drawings in which: i

Fig. 1 is a perspective'viewof' the connector'body showing the locking screw detached;-

Fig. 2 is a perspective viewof the lever clamp which fits in the connector body and is acted on by the locking. screw;

Fig. '3 is a cross section on 'line 3--3 of Fig. 7;

Fig. 4 is a cross section on line 4-4 of Fig. 7;

Fig. 5 is aside elevation'of the'entireconnector showing the lever clamp assembled thereon with the connector" locked in a hole of an outlet box and anchoringie 'cnble totheoutlet box; I

Fig. 6 is an assembly view similar to Fig. 5 but showing a cable of smaller diameter secured by the connector clamp; and

Fig. 7 is a perspective view of the variant form of the lever clamp.

In accordance with my invention there is provided an electric connector comprising a body member, generally indicated at 9 which is of a general tubular configuration'as best shown in Fig. l and which provides a bore 10 for receiving a cable. At one side of the annular wall of this body member there is provided a lever-clamp receiving slot 11 which extends from the front end 12 to the rear end 13 thereof.

Said bore is of the uniform diameter with the exception of an annular reduction at the front end 12, denoted at 14, which forms an interrupted collar 15 and an inner abutment shoulder 16. This reduced collar portion is inserted into the cable receiving aperture 17 in the wall 18 of a standard outlet box shown in Figs. 5 and 6.

Integrated with the collar 15 there is supplied a pair of radial lugs as at 19 which are spaced from the abutment shoulder and disposed on the side of said collar remote from said slotted portion 11. 2 These lugs engage an edge portion of the hole 17 in the outlet box wall 18 at the inner side thereof.

Parallel bridge-forming walls 20 extend outwardly from the slotted portion 11 of said body member 9 and terminate short of the collar 15 at the front end. Spaced walls 20 are joinedby a crossmembcr 21 exposed at the rear of said body member and having forwardly located journalling openings 22 therein which are transversely aligned. A screw 23 is threadedly. engaged'in the bridge-forming wall 20 and has its inner ends suited to project into the bore 10 when the screw is tightened, as shown in Figs. 5 and 6.

The lever clamp is disposed freely in the slotted portion 11 of the body member 9 to extend lengthwise thereof-see Figs. 5 and 6. The lever clamp, generally denoted at 24, comprises an elongated plate 25 having a front end 26 and a rear end 26'. The plate is a metal member desirably fashioned as a stamping by means of suitable dies and includes a pair of aligned trunnions 27 disposed intermediate the length thereof and extended outwardly from the sides of the plate.

Said trunnions are seated in the openings 22 of the bridge walls to pivotally mount the lever clamp in the slotted portion of said body member; To provide for assembly of the lever clamp in said body member, the openings 22 are interrupted by lead-in slots 28 which extend upwardly in the bridge-forming walls 20 and break therethrough to admit the trunnions 26 respectively, and these slots are desirably of a V-shaped character. Desirably the trunnions have flattened sides as indicated at 29 and these sides reside at an angle to the plane of the plate 25whereby in the normal position of the lever clamp in which it is locked on the outlet box the angle at which the flat sides are disposed serves to prevent the trunnions from being displaced form the openings 22.

At the front end of the plates 26 there is provided a lip 30 for latching engagement with an edge portion of the holes 17 in the outlet wall 18. The latching engagement is'shown in Figs. 5 and 6 and desirably forms a part of a transverse trough 31 which receives the edge portion of the outlet box wall 18. The plate is deformed to provide the trough 31. Desirably the front end'of the plate is supplied with a struck-up reinforcing rib 32 which is adapted to strengthen the trough portion'thereof.

Said plate is'supplied at its rear end with an underlying" return bent section 37 for engaging a cable such u that" indicated at 33, Fig; 5, or at 34 in Fig. 6.

The bight portion 35 of the cable-engaging section 37 is cut away as at 36 in order to weaken it and also to provide clearance for the screw 23 so that said screw may freely pass through. the plate 25 and make contact with the cable-engagingsection 37.. In the form of the:

lever clamp shown in Figs. 2, and 6, the cable-en-ii.

vaging section 37 is deformed into a first arcuate element 38 and a second arcuate element 38. because in tightening the lever clamp on a flexible. metal.- lic cable, such as that indicated at 33 in Fig. 5,. very This is desirable:

little bending action is required on the part of the rev turn-bent cable-engaging section 37 in order to bring about clamping engagement as will be seen from'an inconfiguration and having a lever-clamp receiving slot at one side thereof extending from the front end to the rear end of said body member, said body member having a diametrical reduction at its front end forming a collar and an abutment shoulder, a radial lug on said collar forwardly spaced from said abutment shoulder and disposed on the side of said body member remote from said slotted portion. for engaging an edge portion of said outlet-box aperture, parallel bridge-forming walls extending outwardly from the slotted portion of said body member and joined by a cross member at the rear of said body member, said bridge-forming walls having transversely aligned journalling openings therein; and said spection of Fig. 5.' However, when the connector is used a for a non-metallic cable, which 'is of a less. diameter such as that shown at 34 in .Fig. 6, the return-bent cable-engaging section 37 will flex to a greater extent so that the second arcuate element 38'.is quickly brought to bear on the cable with a desired clamping effect. This is a desirablearrangement and preferably this return-bent cable-engaging section 37 is supplied with a struck-up reinforcing rib 39 and has depending flanges v 40 formed at its side edges which aid in imparting rigidity. throughout the length but not at the bight portion. The only difference in Fig. 7 is that the return-bent cable-engaging section 37 is formed with a single arcuate element and has the reinforcing struck-up rib 39 and the marginal flanges 40 shown in cross section in-Fig. 4. It will be gathered that the lever clamp shown in Fig. 2 is similar in cross section and that the reinforcing rib32 at the front end of the lever clamp which is shown in cross section in Fig. 3, is similar to that of Fig. 2.

From the preceding description it will be manifest that my invention provides a practical and serviceable electrical connection which is inexpensive to manufacture.

What I claim is: r 1. An electric connector for securinga cable to an outlet box having a cable-receiving aperture, said connector comprising a body member and a lever clamp thereon, said body member having a general tubular configuration and having a lever-clamp receiving slot at one side thereof extending from the front end to the rear end of said body member, said bodymember having a diametrical reduction at its front-end forming a-collar and an abutment shoulder, a radial lug on said collar forwardly spaced from said abutment shoulder and-disposed on the side of said body member remote from said slotted portion for engaging an edge portion of said outlet-box aperture, parallel bridge-forming walls extending outwardly from the slotted portion of said body member and joined by a cross member at the rear of said body member, said bridge-forming walls having transversely aligned journalling openings therein; and said lever clamp comprising an elongated plate having a front end and a rear end, a pair of aligned intermediately disposed trunnions extending laterally from said plate and seated in said bridge-wall openings to pivotally mount said lever clamp in said slotted portion of said body member, said plate having at its front end a lip for latching engagement with said edge portion of said outlet-box aperture, and said plate having at its rear end an underlying return-bent cable-engaging section with a lever clamp comprising an elongated plate'having a front end and a rear end, a pair of aligned intermediately disposed trunnions extending laterally from said plate and seated in said bridge-Wall openings to pivotally mount said lever clamp in said slotted portion of said body member, said plate having at its front end a lip for latching'engagement with said edge portion of said outlet-box aperture, and said plate having at its rear end an underlying return-bent cable-engaging section with a bight portion weakened by a cut-away section at the rear end of said plate which provides clearance for a screw depending from said cross member; said cable-engaging section deformed to provide an arcuate element adapted to be brought into clamping engagement with a cable, and a screw threadedly engaged with said cross member-and extending through said cut-away section of said plate and having a free end in abutment with said cable-engaging section for exerting clamping and bending stresses when said screw is tightened.

3. Anelectric connector for securing a cable to an outlet box having a cable-receiving aperture, said connector comprising a body member and a lever clamp thereon, said body memberhaving a general tubular configuration and having'a lever-clamp receiving slot at one side thereof extending from thefront end to the rear end of said body. member, said body member having a diametrical reduction at its front end forming a collar andan abutment shoulder, a radial lug on said collar forwardly spaced from said abutment shoulder and disposed on the side of said body member remote from said slotted portion for engaging an edge portion of said outlet-box aperture, parallel bridge-forming walls extending outwardly from the slotted portion of said body member and joined by a cross member at the rear of said body member, said bridge-forming walls having transversely aligned journalling openings therein; and said lever clamp comprising an elongated plate having a front end and a rear end, a pair of aligned intermediately disposed trunnions extending laterally from said plate and seated in said bridge-wall openings to pivotally mount said lever clamp in said slotted portion of said body member, said ,bent cable-engaging section with a bight portion Weakened by a cut-away section at the rear end of said plate which provides clearance for a screw depending from said cross member; said cable-engaging section deformed bight portion weakened by a cut-away section at'the rear end of said plate which provides clearance for a screw depending from said cross member; and a screw thread---*--- and having a free end in abutment with said cable-' edly engaged on said crossmember and extending through said cut-away section of said plate and having a free end in abutment with said cable-engaging section for exerting clamping and bending stresses when said screw is tightened.

2. An electric connector for securing a cable to an outlet box having a cable-receiving aperture, said connector comprising a body member and a lever clamp thereon, said body memberhaving a; general tubular,

" into first and second arcuate elements, each adapted to be brought into clamping engagement with a cable, and a screw threadedly engaged with saidcross member and extending through said cut-away section of said plate engaging section for exerting clamping and bending stresses when said screw is tightened.

' 4. The structure of claim 3, in which the transversely aligned journalling openings are interrupted by lead-in slots provided in the bridge-forming wall, and in which the intermediately disposed trunnions have flattened sides for enabling them to pass throughsaid lead-in slots for assembling the lever clamp on said body member.

5. The structure of claim 3, in which theelongated plate, which forms the lever clamp, is deformed at its front end to provide a transverse trough which receives the edge portion of said outlet box, and in which a portion of said trough provides said lip.

6. The structure of claim 5, in which a longitudinally extending rib is provided on the elongated plate to strengthen it at the zone of said trunnions and said trough area.

7. The structure of claim 3, in which the plane of the return-bent cable-engaging section of the lever clamp is provided with a reinforcing rib which extends longitudinally.

8. The structure of claim 3, in which the return-bent cable-engaging section of the lever clamp is provided with depending marginal side flanges.

9. A lever clamp for an electric connector having a body with a slotted portion and a cross member fitted with a screw, said lever clamp comprising an elongated plate having a front end and a rear end, a pair of aligned intermediately disposed trunnions extending laterally from said plate and journalled in said slotted portion of said body, said plate having at its front end a lip for latching engagement with an edge portion of an opening in an outlet box, and said plate having at its rear end an underlying return-bent cable-engaging section with a bight portion weakened by a cut-away section at the rear end of said plate which provides clearance for saidscrew whereby said screw may extend through said cut-away section and into abutment with said cable-engaging section for exerting clamping and bending stresses when tightened.

References Cited in the file of this patent UNITED STATES PATENTS 1,732,956 Thomas Oct. 22, 1929 2,457,235 Hochn Dec. 28, 1948 2,639,927 Billeter May 26, 1953 

